Releasable container interlock

ABSTRACT

Apparatus for releasably locking large ocean-type vertically stacked cargo containers to each other. A body is disposed between the containers, spaces the containers apart and is fitted with a cone that can be rotated from an open position into a locked position in which the cone engages an undercut in corner fittings of the container by actuating a handle that protrudes horizontally through a slot-like opening in a side of the body. The body is also fitted with means to secure it to a corner fitting of the lower container at least while the cone locks the upper container to the body.

Unite wt.

Laidley States Patent RELEASABLE CONTAllNER INTERLOCK [75] Inventor: William S. Laidley, Piedmont, Calif.

[73] Assignee: Vulcan Steel Foundary Co., Oakland,

Calif,

[22] Filed: Mar. 13, 1972 [21] Appl. No.: 233,973

[52] [1.8. CI. 24/81 E, l05/366R, 248/361 R [51] lint. Cl B65j l/04 [58] Field of Search 296/35 A; 294/67 R,

294/67 DA; 24/81 E,21l P.2l1 R,81 E; 105/366 A, 366 R, 366 C, 366 E; 280/D1G. 8, 179 A, 179 B, 179 R; 214/38; 287/2; 248/119 [56] References (Iited UNITED STATES PATENTS 2,963,310 12/1960 Abolins 294/67 DA [11 3,753,272 [451 Aug. 21, 1973 3,389,663 6/1968 Gutridge 105/366 R 3,480,174 11/1969 Sherwood 220/1.5 3,612,466 10/1971 Arnold 248/361 R Primary Examiner-Donald A. Griffin Attorney-Stephen S. Townsend et a1.

[57] ABSTRACT Apparatus for releasably locking large ocean-type vertically stacked cargo containers to each other. A body is disposed between the containers, spaces the containers apart and is fitted with a cone that can be rotated from an open position into a locked position in which the cone engages an undercut in corner fittings of the container by actuating a handle that protrudes horizontally through a slot-like opening in a side of the body. The body is also fitted with means to secure it to a corner fitting of the lower container at least while the cone locks the upper container to the body.

18 Claims, 10 Drawing Figures Patented Aug. 21, 1973 2 Sheets-Sheet l FIG 5 l RELEASABLE CONTAINER INTERLOCK BACKGROUND OF THE INVENTION Container shipping, particularly via ocean ships, becomes increasingly important as a result of the economics that can be achieved thereby. The containers, ranging insize from to 40 feet in length, 8 feet in both width and height are stacked one on top of the other. Container alignment and positioning cones are inserted in container corner fittings and precisely align each container with the one below it as the stacks are built to their full height.

During shipment, the containers are subject to vibration, swaying, rolling and pitching motions and the containers in the stacks must therefore be interlocked. In the past containers were interlocked by placing a container on the positioning cone and then pinning it thereto. This requires tedious hand work, often at hazardous heights, is time-consuming and costly. To further economize containerized shipping adjacent container stacks have been moved closer together until by now the stacks are often separated by less than an inch. This provides insufficient clearance to pin the containers in accordance with the prior art.

SUMMARY OF THE INVENTION The present invention provides a container interlock that canbe used on all types of ocean or land going, large shipping containers to interlock the containers in a stack and to lock the lowermost container to a base even though adjacent container stacks may be separated by only an inch or less.

This is accomplished by providing a central member including fixed oblong upper and lower protrusions and an intermediate body for supporting the container. The body has a side opening disposed between the protrusions. Aligned, substantially cylindrical apertures are in ends of the protrusions and have aligned cutbacks. A locking cone is disposed above the upper protrusion and has a base that is complementary to a cross section of the upper protrusion. A shaft depends from the base through the apertures, past an end of the lower protrusion and has a diameter complementary to that of the cylindrical apertures. A flange extends laterally from the shaft and is disposed below the lower protrusion. It has a configuration complementary to that of the cutbacks on the apertures to permit axial withdrawal of the shaft and the cone from the apertures by aligning the flange with the cutbacks. A handle is secured to the shaft and extends laterally therefrom past the open side for rotating the shaft and the cone about the axis of the apertures from an unlocked position in which the base is aligned with the upper protrusion to a locked position in which the base is offset with respect to the upper protrusion so that the cone is disposed within the undercut when the upper protrusion extends into the opening. The container is thereby locked to the body. Means is further provided for releasably securing the downwardly extending protrusion to the fitting of a lower container or a base against vertical movement.

The body separates the containers vertically by one or two inches, which is readily accepted since a slight increase in the overall container stack height does not adversely affect the capacity of the vessel. The movable container interlocking cone is actuated with a handle disposed at the narrow side of the container. There is a substantial distance between the narrow end faces of the container stacks to provide clearance for the actuating handle and access for operating it.

The container interlock of the present invention is rugged, simple in construction and therefore of low cost. It performs the necessary container aligning func tion to facilitate container stacking by providing the rotatable cone. The cone doubles as a container interlock after the top container has been positioned. I-Ieretofore necessary tedious hand work, inserting pins in inaccessible places and at hazardous heights and significant costs are thereby eliminated. Thus, the present invention increases the economics of todays containerized shipping.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of two vertically stacked containers interconnected with the container lock of the present invention;

FIG. 2 is a cross-sectional, side elevational view of the container lock of the present invention;

FIG. 3 is a cross-sectional, front elevational view of the container lock of FIG. 2;

FIG. 4 is a plan view of the container lock in its unlocked position;

FIG. 5 is a plan view similar to FIG. 4 but shows the lock in its locked position;

FIG. 6 is a bottom end view of the container lock of the present invention;

FIG. 7 is a plan view of the main body of the container lock with the alignment and locking cone removed;

FIG. 8 is a fragmentary, front elevational view ofthe container lock illustrated in FIG. 4;

FIG. 9 is a fragmentary bottom end view of the container lock and illustrates the position of flanges securing the cone to the main body when the cone is in its unlocked psoition shown in FIG. 4; and

FIG. 10 is a fragmentary view similar to FIG. 9 but illustrates the position of the flanges when the cone is in its locked position (shown in FIG. 5).

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring first to FIG. 1, a plurality of cargo shipping and storage containers 10 are placed on top of each other in a stack 12. The containers have the usual dimensions, that is, an 8X8 foot cross section and have lengths of between 10 to 40 feet. The containers rest on a support 14 of a container vessel 16 or the like. Each container includes upper and lower corner fittings 18 which have vertically oriented, oblong apertures 20, that is, apertures having parallel sides 21 and curved ends 22. An upright container mounting device 24 connects each adjacent set of corner fittings. A lower half 26 of each device is secured to the lower container or the floor and an upper half 28 aligns the adjacent upper container with respect to the lower one and secures the two against relative horizontal movement. The present invention provides locking means 30 for securing the containers to each other against relative vertical movements.

Referring to FIGS. 2-8, mounting device 24 is defined by a central body 32 which has upwardly and downwardly facing flat and parallel faces 34 and 36, respectively. An upper protrusion 38 has an outline complementary to that of oblong corner fitting opening 20 and terminates in a flat upper end 40.

A lower protrusion or plug 42 depends downwardly from lower body face 36 in axial alignment with upper protrusion 38 and has a generally rectangular cross section that is defined by two sets of diagonally opposed, parallel side portions 44 and 46. The first set 44 is parallel to sides 48 of upper protrusion 38 and second set 46 is inclined with respect to the first set by an angle of at least about 30 and preferably about 45. A flange member 50 defining the lowermost end of plug 42 projects outwardly from the first parallel side portions 44 in continuation of and preferably parallel to the second side portion set.

The body 32 and upper and lower protrusions 38 and 42 are preferably heavy walled castings or the like and are hollow. The body itself includes a vertical sidewall 52 which extends over three sides thereof and terminates short of the fourth side to define an open side or elongate slot 54 providing access from the exterior of the block to its interior. The slot faces in the direction of the long axis of the cross section of upper protrusion 38 as best seen in FIG. 8. Upper protrusion end 40 and a lower protrusion end 56 include aligned cylindrical apertures 58 which have cutbacks 60 for purposes more fully described hereinafter.

A container aligning and locking member 62 is defined by a cone 64 and a shaft 66 integrally constructed with the cone which depends downwardly from a cone base 68. The cone base has an outline complementary to, that is which is the same as, the cross section of upper protrusion 38. Shaft 66 is journalled in apertures 58. A lower end 70 of the shaft includes a pair of opposite transversely extending flanges 70 (see FIGS. 9 and which are dimensioned so that they can pass through cutbacks 60 of cylindrical apertures 58.

An intermediate portion of the shaft mounts a horizontal handle 72 which extends outwardly through and past body slot 54. The handle can be grasped on the exterior of the body and rotated from one end 74 to another end 76 of the slot. In this manner cone 64 can be rotated from a position in which it is aligned with upper protrusion 38 (shown in FIG. 4) through an angle of preferably 90 into a position in which it is perpendicular to the upper protrusion (shown in FIG. 5).

The handle is preferably permanently secured to shaft 66 as by first inserting the shaft through apertures 58 and then welding the handle end to a suitable bore in the shaft. Alternatively, the handle can be threadably or otherwise demountably attached to the shaft.

Referring now particularly to FIGS. 9 and 10, flanges 70 on the lower end of shaft 66 are angularly offset relative to cone 64 by several degrees, say by to about 30. The angular offset of the flanges is in the direction of rotational movement of the cone from the aligned to the perpendicular positions (shown in FIGs. 4 and 5). The flanges are spaced from cone base 68 a distance slightly greater than the spacing between ends 40 and 56 of the upper and lower protrusions, respectively, so that the flanges are disposed below the lower end of the lower protrusion. Thus, during normal use of the block within the rotational limits set by slot ends 74 and 76 the flanges are always offset from aperture cutbacks 60. Thus, cone 64 and shaft 66 are effectively locked to body 32 and protrusions 38 and 42.

Referring now to FIGS. 2-10, the container interlock of the present invention is installed and used as follows. Block 24 is placed on top of an upper corner fitting l8 ofa container (or ofa like fitting mounted to ship floor 14) and rotated about a vertical axis to align plug sides 46 with oblong aperture 20 in the corner fitting. When so positioned, body 32 is rotated with respect to sides of the container by the same angle as the angular offset between lower plug sides 44 and 46. The block is now lowered into the corner fitting until lower body face 36 rests on top of the corner fitting. The first set of plug sides 44 is angularly inclined with respect to straight sides 21 of the corner fitting opening and does not obstruct the lowering of the block. Thereafter, the block is rotated until the second set 44 of parallel lower plug sides engage sides 21 of the corner fitting aperture. This locks the block against vertical or transverse motion to the lower corner fitting and aligns body 32 with the fitting.

The handle 72 is at righthand slot end 76 as shown in FIG. 4 to align the cone with the upper protrusion. Thereafter the next container is lowered. Cone 64 facilitates the engagement of the oblong aperture in the lower comer fitting and continued downward motion of the container automatically aligns the container with upper protrusion 38 until the lower face of the corner fitting on the upper container rests on upper face 34 of body 32. In this position, upper end surface 40 of protrusion 38 is substantially aligned, that is, it is just slightly above a flat surface 78 of corner fitting 80 where aperture 20 terminates. That flat surface defines a recessed portion on undercut 18 of the corner fitting. An operator now moves handle 72 from righthand corner 76 to lefthand corner 74 of body slot 54. Shaft 66 and cone 64 are thereby rotated to position the cone perpendicular with respect to upper protrusion 38 and place those portions of the cone which extend beyond the outline of the upper protrusion in corner fitting undercut 80. Since shaft 66 is secured against axial movements by flanges 70 on its lower end, the upper container is now secured against vertical movement relative to body 32 and, since the body is secured against vertical movement to the lower corner fitting, the upper container is secured against vertical movements to the lower container. In this manner, all relative motions between the containers is prevented.

To eliminate accidental rotation of cone 64 and shaft 66 and a resulting loss of the container interlock handle 70 is constructed of a relatively resilient material, such as steel bar, and positioned closely adjacent a lower side 82 of slot 54. A pair of locking blocks 84 are positioned in the normal path of the handle as it moves between slot ends 74 and 76 adjacent each slot end but spaced therefrom so that vertical walls of the blocks define handle receiving spaces 86. Sides 88 of the blocks generally facing toward each other are sloped from lower slot side 82 to the uppermost part of the block.

When the handle is in a receiving space 86 it is locked against moving in slot 54. Cone 64 is thereby locked in either its aligned or perpendicular position as illustrated in FIGS. 4 and 5. To release the cone and move it into the other position the operator must grip the free end of handle 72 and lift it upwardly to resiliently deflect the handle until it clears top surface 90 of block 84. Thereafter he can release the handle and move it laterally towards the other end of the slot. First the handle will glide down the sloped surface of the first locking block and thereafter up along the sloped surface of the second block to automatically resiliently deflect the handle again. The handle will then automatically snap into the other receiving space to lock the cone in its other position. The snapping action is of importance since it physically and audibly indicates to the operator that he has moved the handle a sufficient distance to lock it. This helps prevent careless release of the handle short of its locked position.

l claim:

1. A container lock for securing an upper container against relative movement with respect to a base, the container having a corner fitting at a lower container corner, the corner fitting including an oblong, vertical opening terminating in an undercut, the lock comprising a body for supporting an underside of the corner fitting on the base, the body including a horizontally oriented slot communicating an interior of the body with the exterior thereof, a protrusion having a cross section complementary to that of the opening for extending into the opening, the protrusion having a height slghtly greater than the spacing between the underside of the corner fitting and the undercut, a locking member rotatable with respect to the body and the protrusion about an upright axis, means securing the member to the body against axial movement, the member having a configuration permitting it to pass through the opening and for positioning a portion of the member in the undercut to thereby lock the body to the container, the member including a shaft portion extending into the body interior, a resiliently flexible actuating handle secured to the shaft portion and extending through the slot for rotating the member about the upright axis within the limits defined by the slot, stop blocks adjacent each end of the slot, the blocks having a first sloping surface facing each other and a second, substantially vertical surface spaced from the adjoining slot ends a sufficient distance to define spaces for the positioning of the handle between the slot ends and the vertical surfaces, the blocks further having a height so that movement of the handle in the slot causes a transverse deflection of the handle along the sloping surfaces, a subsequent resilient position of the handle in the spaces, and a resulting locking of the handle in one or the other position, and means for securing the body to the base.

2. Apparatus for locking a large ocean-type shipping container to a base or to a lower container, the container including a standard corner fitting having an oblong opening and an undercut, the apparatus comprising: a body having parallel faces for placement against lower fitting means having an oblong opening and an underside of the comer fitting, aligned first and second protrusions extending from the faces dimensioned for positioning within the openings, the first protrusion being defined by a lower section which is angularly offset with respect to the second protrusion and which has substantially the same cross section as the second protrusion, and an upper section terminating at the body face which is aligned with the second protrusion and which has a .cross section that is wholly within an outline of the lower section so that the apparatus can be secured to the fitting means by. first aligning the lower section with the opening in the fitting means, placing the lower body face against the fitting means, and thereafter rotating the apparatus about a vertical axis until the upper section engages walls of the opening whereby the lower section is disposed in an undercut of the fitting means and prevents axial movement of the apparatus with respect to the fitting means, a locking cone disposed at an end of the second protrusion, the

cone having a base of substantially the same outline as a cross section of the second protrusion, shaft means depending from the cone, means mounting the shaft means for rotation with respect to the body and the protrusions, and means on the exterior of the body for rotating the cone from an unlocked position aligned with the upper protrusion to a locked position in which the cone is angularly offset from the protrusion.

3. Apparatus according to claim 2 wherein the means mounting the shaft means to the body comprises flange means extending laterally from the shaft means, and means fixed with respect to the body for engaging the flange means at least when the cone is angularly offset with respect to the second protrusion to thereby prevent axial cone movements when the cone is in a locking position.

4. Apparatus according to claim 2 including spring means for locking the cone against accidental rotatable movement at least when the cone is angularly offset with respect to the second protrusion.

5. Apparatus according to claim 4 wherein the body includes a horizontally oriented opening, and wherein the cone rotating means comprises a handle secured to the shaft means, and extending through the opening to the exterior of the body.

6. Apparatus according to claim 5 wherein the spring means is defined by the handle and the handle has an elongate configuration and is constructed of a resiliently deformable material, and including means for locking the handle against accidental movement when the handle is in its relaxed position.

7. Apparatus for vertically interlocking containers with standard ocean container corner fittings having a vertically oriented oblong opening and an undercut, the apparatus comprising: a central member including ,fixed oblong upper and lower protrusions and an intermediate body for supporting the container, the body including an open side disposed between the protrusions and aligned, substantially cylindrical apertures defined in ends of the protrusions, the apertures including aligned cutback portions, a locking cone disposed above the upper protrusion and having a base that is complementary to a cross section of the upper protrusion, a shaft depending from the base through the apertures and past an end of the lower protrusion, the shaft having a diameter complementary to the diameter of the cylindrical apertures and at least one flange extending laterally from the shaft and disposed below the lower protrusion, the flange having a configuration complementary to that of the cutbacks on the apertures to permit axial withdrawal of the shaft and the cone from the apertures by aligning the flange with the cutbacks, and a handle secured to the shaft and extending laterally therefrom past the open side for rotating the shaft and the cone about the axis of the apertures from an unlocked position in which the base is aligned with the upper protrusion to a locked position in which the base is offset with respect to the upper protrusion so that the cone is disposed within the undercut when the upper protrusion extends into the opening whereby the corresponding container is locked to the body, and means for releasably securing the downwardly extending protrusion to a lower fitting of a lower container or a base against vertical movement.

8. Apparatus according to claim 7 including means for releasably retaining the handle adjacent one or the other end of the open side to lock the cone in an open or a closed position and prevent accidental release of the container interlock, the handle retaining means including means for indicating to an operator that the handle is in a locked position.

9. Apparatus acording to claim 8 wherein the handle is laterally resilient, and wherein the handle retaining means comprises means positioned in the normal path of the handle as it moves between ends of the open body side for retaining the handle in one of the two positions so that release of the handle from such positions requires the application ofa force to deflect the handle and clear the last mentioned means.

10. Apparatus according to claim 7 wherein the open side is positioned to face in the direction of a container end when the upper protrusion engages the opening.

11. Apparatus according to claim 7 wherein the open side faces in the direction of a longer axis of the cross section of the upper protrusion.

12. A container lock for securing an upper container against relative movement with respect to a base, the container having a corner fitting at a lower container corner, the corner fitting including an oblong, vertical opening terminating in an undercut, the lock comprising a body for supporting an underside of the comer fitting on the base, the body including a horizontally oriented slot communicating an interior of the body with the exterior thereof, a protrusion having a cross section complementary to that of the opening for extending into the opening, the protrusion having a height slightly greater than the spacing between the underside of the corner fitting and the undercut, a locking member rotatable with respect to the body and the protrusion about an upright axis between first and second positions, means securing the member to the body against axial movement, the member having a configuration permitting it to pass through the opening and for positioning a portion of the member in the undercut to thereby lock the body to the container when it is in one of the positions, the member including a shaft portion extending into the body interior, spring means cooperating with the shaft portion for opposing rotatable shaft movements when the member is in one or the other of the positions, control means permitting the spring means to stay in a relatively unstressed state when the member is in one or the other of said positions and placing the spring means in a relatively stressed state for movement of the member from one of said positions to the other one, and means for securing the body to the base.

13. A container lock according to claim 12 wherein the control means includes two surfaces that are angularly inclined with respect to each other.

14. A container lock according to claim 12 wherein the control means is disposed in the slot.

15. A container lock according to claim 14 wherein the spring means is defined by a resilient handle secured to the shaft portion and extending through the slot.

16. A container lock according to claim 15 wherein the control means comprises means disposed between ends of the slot for intercepting the handle during movements between the slot ends and deflecting the handle into its relatively stressed state.

17. A container lock for securing an upper container against relative movement with repsect to a base, the container having a corner fitting at a lower container corner, the corner fitting including an oblong, vertical opening terminating in an undercut, the lock comprising a body for supporting an underside of the comer fitting on the base, the body including a horizontally oriented slot communicating an interior of the body with the exterior thereof, a protrusion having a cross section complementary to that of the opening for extending into the opening, the protrusion having a height slightly greater than the spacing between the underside of the corner fitting and the undercut, a locking member rotatable with respect to the body and the protrusion about an upright axis, means securing the member to the body against axial movement, the member having a configuration permitting it to pass through the opening and for positioning a portion of the member in the undercut to thereby lock the body to the container, the member including a shaft portion extending into the body interior, a resiliently flexible actuating handle secured to the shaft portion and extending through the slot for rotating the member about the upright axis within the limits defined by the slot, means disposed adjacent each end of the slot for intercepting movements of the handle within the slot and for deflecting the handle from its relaxed position, the intercepting means terminating short of the slot ends a sufficient distance to define spaces for positioning of the relaxed handle between the slot ends and the intercepting means so that a resilient positioning of the handle in the spaces results in a corresponding locking of the handle in one or the other position, and means for securing the body to the base.

18; Apparatus according to claim 17 wherein the intercepting means includes sloped surfaces to facilitate the deflection of the handle. 

1. A container lock for securing an upper container against relative movement with respect to a base, the container having a corner fitting at a lower container corner, the corner fitting including an oblong, vertical opening terminating in an undercut, the lock comprising a body for supporting an underside of the corner fitting on the base, the body including a horizontally oriented slot communicating an interior of the body with the exterior thereof, a protrusion having a cross section complementary to that of the opening for extending into the opening, the protrusion having a height slghtly greater than thE spacing between the underside of the corner fitting and the undercut, a locking member rotatable with respect to the body and the protrusion about an upright axis, means securing the member to the body against axial movement, the member having a configuration permitting it to pass through the opening and for positioning a portion of the member in the undercut to thereby lock the body to the container, the member including a shaft portion extending into the body interior, a resiliently flexible actuating handle secured to the shaft portion and extending through the slot for rotating the member about the upright axis within the limits defined by the slot, stop blocks adjacent each end of the slot, the blocks having a first sloping surface facing each other and a second, substantially vertical surface spaced from the adjoining slot ends a sufficient distance to define spaces for the positioning of the handle between the slot ends and the vertical surfaces, the blocks further having a height so that movement of the handle in the slot causes a transverse deflection of the handle along the sloping surfaces, a subsequent resilient position of the handle in the spaces, and a resulting locking of the handle in one or the other position, and means for securing the body to the base.
 2. Apparatus for locking a large ocean-type shipping container to a base or to a lower container, the container including a standard corner fitting having an oblong opening and an undercut, the apparatus comprising: a body having parallel faces for placement against lower fitting means having an oblong opening and an underside of the corner fitting, aligned first and second protrusions extending from the faces dimensioned for positioning within the openings, the first protrusion being defined by a lower section which is angularly offset with respect to the second protrusion and which has substantially the same cross section as the second protrusion, and an upper section terminating at the body face which is aligned with the second protrusion and which has a cross section that is wholly within an outline of the lower section so that the apparatus can be secured to the fitting means by first aligning the lower section with the opening in the fitting means, placing the lower body face against the fitting means, and thereafter rotating the apparatus about a vertical axis until the upper section engages walls of the opening whereby the lower section is disposed in an undercut of the fitting means and prevents axial movement of the apparatus with respect to the fitting means, a locking cone disposed at an end of the second protrusion, the cone having a base of substantially the same outline as a cross section of the second protrusion, shaft means depending from the cone, means mounting the shaft means for rotation with respect to the body and the protrusions, and means on the exterior of the body for rotating the cone from an unlocked position aligned with the upper protrusion to a locked position in which the cone is angularly offset from the protrusion.
 3. Apparatus according to claim 2 wherein the means mounting the shaft means to the body comprises flange means extending laterally from the shaft means, and means fixed with respect to the body for engaging the flange means at least when the cone is angularly offset with respect to the second protrusion to thereby prevent axial cone movements when the cone is in a locking position.
 4. Apparatus according to claim 2 including spring means for locking the cone against accidental rotatable movement at least when the cone is angularly offset with respect to the second protrusion.
 5. Apparatus according to claim 4 wherein the body includes a horizontally oriented opening, and wherein the cone rotating means comprises a handle secured to the shaft means, and extending through the opening to the exterior of the body.
 6. Apparatus according to claim 5 wherein the spring means is defined by the handle and the handle has an elongate configuration and is Constructed of a resiliently deformable material, and including means for locking the handle against accidental movement when the handle is in its relaxed position.
 7. Apparatus for vertically interlocking containers with standard ocean container corner fittings having a vertically oriented oblong opening and an undercut, the apparatus comprising: a central member including fixed oblong upper and lower protrusions and an intermediate body for supporting the container, the body including an open side disposed between the protrusions and aligned, substantially cylindrical apertures defined in ends of the protrusions, the apertures including aligned cutback portions, a locking cone disposed above the upper protrusion and having a base that is complementary to a cross section of the upper protrusion, a shaft depending from the base through the apertures and past an end of the lower protrusion, the shaft having a diameter complementary to the diameter of the cylindrical apertures and at least one flange extending laterally from the shaft and disposed below the lower protrusion, the flange having a configuration complementary to that of the cutbacks on the apertures to permit axial withdrawal of the shaft and the cone from the apertures by aligning the flange with the cutbacks, and a handle secured to the shaft and extending laterally therefrom past the open side for rotating the shaft and the cone about the axis of the apertures from an unlocked position in which the base is aligned with the upper protrusion to a locked position in which the base is offset with respect to the upper protrusion so that the cone is disposed within the undercut when the upper protrusion extends into the opening whereby the corresponding container is locked to the body, and means for releasably securing the downwardly extending protrusion to a lower fitting of a lower container or a base against vertical movement.
 8. Apparatus according to claim 7 including means for releasably retaining the handle adjacent one or the other end of the open side to lock the cone in an open or a closed position and prevent accidental release of the container interlock, the handle retaining means including means for indicating to an operator that the handle is in a locked position.
 9. Apparatus acording to claim 8 wherein the handle is laterally resilient, and wherein the handle retaining means comprises means positioned in the normal path of the handle as it moves between ends of the open body side for retaining the handle in one of the two positions so that release of the handle from such positions requires the application of a force to deflect the handle and clear the last mentioned means.
 10. Apparatus according to claim 7 wherein the open side is positioned to face in the direction of a container end when the upper protrusion engages the opening.
 11. Apparatus according to claim 7 wherein the open side faces in the direction of a longer axis of the cross section of the upper protrusion.
 12. A container lock for securing an upper container against relative movement with respect to a base, the container having a corner fitting at a lower container corner, the corner fitting including an oblong, vertical opening terminating in an undercut, the lock comprising a body for supporting an underside of the corner fitting on the base, the body including a horizontally oriented slot communicating an interior of the body with the exterior thereof, a protrusion having a cross section complementary to that of the opening for extending into the opening, the protrusion having a height slightly greater than the spacing between the underside of the corner fitting and the undercut, a locking member rotatable with respect to the body and the protrusion about an upright axis between first and second positions, means securing the member to the body against axial movement, the member having a configuration permitting it to pass through the opening and for positioning a portion of the member in the undercut to thereby locK the body to the container when it is in one of the positions, the member including a shaft portion extending into the body interior, spring means cooperating with the shaft portion for opposing rotatable shaft movements when the member is in one or the other of the positions, control means permitting the spring means to stay in a relatively unstressed state when the member is in one or the other of said positions and placing the spring means in a relatively stressed state for movement of the member from one of said positions to the other one, and means for securing the body to the base.
 13. A container lock according to claim 12 wherein the control means includes two surfaces that are angularly inclined with respect to each other.
 14. A container lock according to claim 12 wherein the control means is disposed in the slot.
 15. A container lock according to claim 14 wherein the spring means is defined by a resilient handle secured to the shaft portion and extending through the slot.
 16. A container lock according to claim 15 wherein the control means comprises means disposed between ends of the slot for intercepting the handle during movements between the slot ends and deflecting the handle into its relatively stressed state.
 17. A container lock for securing an upper container against relative movement with repsect to a base, the container having a corner fitting at a lower container corner, the corner fitting including an oblong, vertical opening terminating in an undercut, the lock comprising a body for supporting an underside of the corner fitting on the base, the body including a horizontally oriented slot communicating an interior of the body with the exterior thereof, a protrusion having a cross section complementary to that of the opening for extending into the opening, the protrusion having a height slightly greater than the spacing between the underside of the corner fitting and the undercut, a locking member rotatable with respect to the body and the protrusion about an upright axis, means securing the member to the body against axial movement, the member having a configuration permitting it to pass through the opening and for positioning a portion of the member in the undercut to thereby lock the body to the container, the member including a shaft portion extending into the body interior, a resiliently flexible actuating handle secured to the shaft portion and extending through the slot for rotating the member about the upright axis within the limits defined by the slot, means disposed adjacent each end of the slot for intercepting movements of the handle within the slot and for deflecting the handle from its relaxed position, the intercepting means terminating short of the slot ends a sufficient distance to define spaces for positioning of the relaxed handle between the slot ends and the intercepting means so that a resilient positioning of the handle in the spaces results in a corresponding locking of the handle in one or the other position, and means for securing the body to the base.
 18. Apparatus according to claim 17 wherein the intercepting means includes sloped surfaces to facilitate the deflection of the handle. 